Antonio’s Recommended Reading, Research, & Review for Human Performance - Issue #02 | July 2022

Every month, XSENSOR's Sports Performance Science Contributor, Antonio Robustelli, MSc, CSCS (Sports Performance Scientist & Technologist with OmniAthlete Performance Concept), will offer his take on essential and recommended reading, research, and review for plantar pressure applications using gait analysis for athletes.

Be sure to tune in to get the abstracts, summaries, and key takeaways or read the full studies at your own pace.

Research Title: Distribution of Plantar Pressure in Soccer Players

Authors: Hawrylak A., Brzezna A., Chromik K.

Journal: International Journal of Environmental Research and Public Health

Publication Year: 2022

Abstract

Background: The aim of this study was to evaluate differences in the static and dynamic distribution of foot pressure on the ground and to investigate the relationships between Body Mass Index (BMI) and mean variables of plantar pressure between soccer players and their non-athlete peers.

Methods: The study involved 18 first-division Polish soccer players and 30 non-athlete physiotherapy students. The research experiment was conducted using the FreeMed platform. Basic descriptive statistics were calculated to summarize the variables. Additionally, in the static and dynamic tests, Spearman's rank correlations between BMI and plantar load were calculated.

Results: Statistically significant differences between groups were observed in the loading of the dominant limb. A statistically significant correlation between BMI and loading of both limbs was found in the static test and between BMI and loading of the dominant limb in the dynamic test.

Conclusions: The baropodometric mat used in our study helped determine the plantar pressure distribution of soccer players and their non-athlete peers. Correlation analysis revealed that BMI was only associated with the mean plantar pressure of the dominant limb in the control group. Further research on a larger group of athletes is needed to determine how much sporting activity may affect the development to modifications within feet in soccer players.

Why the Study Is Relevant

This study aimed to investigate the pressure distribution within the three zones of the foot (rearfoot, midfoot, and forefoot) in soccer players during static and dynamic assessment.

Even if it’s important to understand if a correlation exists between sport-specific movements in soccer and changes in pressure distribution and loads within the foot, especially in the context of injury reduction, it is also necessary to consider the chaotic nature of the sport.

The study looks poorly designed as the sample size is low in both groups and the design is not experimental and it’s not involving an independent variable to understand how the pressure distribution changes after some specific training over time. In fact, we only have a snapshot of plantar pressure distribution in a specific moment in time.

Also, the dynamic tests performed on the mat in a strictly controlled movement does not match the movements taking place on the pitch during practice and competition. Also, the barefoot walking affect the way the foot impacts the ground thus giving a different picture respect to what happens with soccer shoes.

Summary

Soccer is characterized by high intensity running, quick accelerations, jumps, landings, and changes of direction, thus exposing players to high loads on joints and muscle structures.

This study aimed to investigate if a relationship exists between BMI and plantar pressure distribution.

Key Takeaways

• BMI is only associated with mean plantar pressure of dominant limb in the control group.

Research Title: Medical and Biomechanical Risk Factors for Incident Bone Stress Injury in Collegiate Runners: Can Plantar Pressure Predict Injury?

Authors: Wilzman AR., Tenforde AS., Troy KL., Hunt K., Fogel N., Roche MD., Kraus E., Trikha R., Delp S., Fredericson M.

Journal: Orthopaedic Journal of Sports Medicine

Publication Year: 2022

Abstract

Background: Bone Stress Injury (BSI) is a common reason for missed practices and competitions in elite track and field runners.

Hypothesis: It was hypothesized that, after accounting for medical risk factors, higher plantar loading during running, walking, and athletic movements would predict the risk of future BSI in elite collegiate runners.

Study Design: Cohort study; Level of evidence, 2.

Methods: A total of 39 elite collegiate runners (24 male, 15 female) were evaluated during the 2014-2015 academic year to determine the degree to which plantar pressure data and medical history (including Female and Male Athlete Triad risk factors) could predict subsequent BSI. Runners completed athletic movements while plantar pressures and contact areas in 7 key areas of the foot were recorded, and the measurements were reported overall and by specific foot area. Regression models were constructed to determine factors related to incident BSI.

Results: 21 runners (12 male, 9 female) sustained ≥1 incident BSI during the study period. Four regression models incorporating both plantar pressure measurements and medical risk factors were able to predict the subsequent occurrence of (A) BSIs in female runners, (B) BSIs in male runners, (C) multiple BSIs in either male or female runners, and (D) foot BSIs in female runners. Model A used Maximum Mean Pressure (MMP) under the first metatarsal during a jump takeoff and only misclassified 1 female with no BSI. Model B used increased impulses under the hindfoot and second through fifth distal metatarsals while walking, and under the lesser toes during a cutting task, correctly categorizing 83.3% of male runners. Model C used higher medial midfoot peak pressure during a shuttle run and triad cumulative risk scores and correctly categorized 93.3% of runners who did not incur multiple BSIs and 66.7% of those who did. Model D included lower hindfoot impulses in the shuttle run and higher first metatarsal MMP during treadmill walking to correctly predict the subsequent occurrence of a foot BSI for 75% of women and 100% without.

Conclusion: The models collectively suggested that higher plantar pressure may contribute to risk for BSI.

Why the Study Is Relevant

This study aimed to investigate the potential use of plantar pressure measurement as a method to predict the risk of BSI in track and field runners.

The paper introduces a relevant topic in today’s applied sport science and the study has a design with a good sample size and a follow-up lasting 4 years after the baseline measurement of plantar pressure data.

Further investigation is needed in the future to improve data collection and quality, including the simultaneous measurement of both feet and a running task to be performed on a track and not on a treadmill.

Summary

BSI is a form of overuse injury which is very common in the lower extremities of elite distance runners.

This study aimed to understand the predictive value of dynamic plantar pressure data in the risk of developing a BSI.

The researchers developed four predictive models and they found that plantar pressure was able to predict incident BSI in male and female runners.

Key Takeaways

• Runners who develop BSI have higher peak pressures or impulses during walking, jumping, cutting, and shuttle tasks.
• Higher forefoot loading can be indicative of incident BSI in the feet.

Research Title: Change of In-Shoe Plantar Pressure According to Type of Shoes (Flat Shoes, Running Shoes, and High Heels)

Authors: Yun Jae Cho, Dong-Woo Lee, Hyuck Soo Shin, Yoon Bin Hwang, Dong Oh Lee, Dae-Yoo Kim, Dong Yeon Lee

Journal: Clinics in Orthopaedic Surgery

Publication Year: 2022

Abstract

Background: The type of footwear is one of several factors that affect foot pressure. Despite its usefulness in identifying pathology and preventing and treating foot-related diseases, the type of shoes has been investigated and compared in only a few studies. This study aimed to investigate differences in plantar pressure, induced by flat, running, and high-heeled shoes in healthy, young women.

Methods: A total of 27 healthy women (27 feet) with a mean age of 21.5 ± 2.03 years were included in this study. Based on demographic data, radiologic measurements, clinical scores, temporal gait parameters, and kinematic parameters of gait, we confirmed the participants had normal feet. Then, pedobarographic data were measured by dividing each foot into seven regions to compare the three types of shoes. Peak plantar pressure and pressure-time integral were calculated using the Pedar-X system. The one-way analysis of variance and the Kruskal-Wallis test with Mann Whitney U-test were used for statistical analyses.

Results: Regarding the 7 regions of the foot, flat shoes resulted in a significantly higher pressure than running shoes in the hallux and lesser toes and the highest pressure in the metatarsal head (MTH) 3-5 and the hindfoot. In contrast, in the MTH 1 and MTH 2 regions, the high-heeled shoes had the highest measured pressure, followed by the flat shoes. Lastly, there was no high pressure in running shoes in any region except for the midfoot compared to the other shoes.

Conclusions: It can be inferred from our findings that flat and high-heeled shoes can generate a considerable burden on specific parts of the foot, which will aid in choosing appropriate shoes. Also, wearing running shoes places less burden on the overall foot.

Why the Study Is Relevant

This study aimed to investigate the influence of different footwear in plantar pressure values in healthy young women.

The research is well designed while the sample size could have been larger and representative of a sporting population.

While the subjects included in the study were defined as “healthy young women”, no mention is present about their physical activity habits and status and further development are needed to address this topic in a sporting population where the impact of different shoes can dramatically affect the performance output.

Summary

Foot-related diseases can change in response to plantar pressure and the type of footwear worn has been hypothesized to influence gait mechanics and pressure distribution.

This research showed that high-heeled shoes results in high pressure in first and second MTH while flat shoes results in high pressure in the hallux and hindfoot.

Key Takeaways

• Flat and high-heeled shoes can generate high loads and pressures in specific parts of the foot.

• Plantar pressure response with different footwear can help in the process of shoe fitting.

Read the full study.